Rename GistTranslateStratnum() to GistTranslateCompareType()

Follow up to commit 630f9a43ce.  The previous name had become
confusing, because it doesn't actually translate a strategy number but
a CompareType into a strategy number.  We might add the inverse at
some point, which would then probably be called something like
GistTranslateStratnum.

Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com

src/backend/access/gist/gistutil.c

@@ -1095,7 +1095,7 @@ gist_stratnum_common(PG_FUNCTION_ARGS)
  * Returns InvalidStrategy if the function is not defined.
  */
 StrategyNumber
-GistTranslateStratnum(Oid opclass, CompareType cmptype)
+GistTranslateCompareType(Oid opclass, CompareType cmptype)
 {
 	Oid			opfamily;
 	Oid			opcintype;

src/backend/commands/indexcmds.c

@@ -2455,7 +2455,7 @@ GetOperatorFromCompareType(Oid opclass, Oid rhstype, CompareType cmptype,
 		 * For now we only need GiST support, but this could support other
 		 * indexams if we wanted.
 		 */
-		*strat = GistTranslateStratnum(opclass, cmptype);
+		*strat = GistTranslateCompareType(opclass, cmptype);
 		if (*strat == InvalidStrategy)
 		{
 			HeapTuple	tuple;

src/backend/commands/tablecmds.c

@@ -10016,7 +10016,7 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			 * ask the opclass what number it actually uses instead of our RT*
 			 * constants.
 			 */
-			eqstrategy = GistTranslateStratnum(opclasses[i], cmptype);
+			eqstrategy = GistTranslateCompareType(opclasses[i], cmptype);
 			if (eqstrategy == InvalidStrategy)
 			{
 				HeapTuple	tuple;
@@ -10041,7 +10041,7 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			 * other index AMs support unique indexes.  If we ever did have
 			 * other types of unique indexes, we'd need a way to determine
 			 * which operator strategy number is equality.  (We could use
-			 * something like GistTranslateStratnum.)
+			 * something like GistTranslateCompareType.)
 			 */
 			if (amid != BTREE_AM_OID)
 				elog(ERROR, "only b-tree indexes are supported for foreign keys");

src/backend/executor/execReplication.c

@@ -57,7 +57,7 @@ get_equal_strategy_number(Oid opclass)
 			ret = HTEqualStrategyNumber;
 			break;
 		case GIST_AM_OID:
-			ret = GistTranslateStratnum(opclass, COMPARE_EQ);
+			ret = GistTranslateCompareType(opclass, COMPARE_EQ);
 			break;
 		default:
 			ret = InvalidStrategy;

src/include/access/gist.h

@@ -248,6 +248,6 @@ typedef struct
 	do { (e).key = (k); (e).rel = (r); (e).page = (pg); \
 		 (e).offset = (o); (e).leafkey = (l); } while (0)
 
-extern StrategyNumber GistTranslateStratnum(Oid opclass, CompareType cmp);
+extern StrategyNumber GistTranslateCompareType(Oid opclass, CompareType cmptype);
 
 #endif							/* GIST_H */